Machine for cutting toothed gearing.



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APPLIATION FILED OGTJB, 1904. .Y

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UNITED sTATris GEORGES NARIHN, UF PAlilS,

rnTnnT orrreir.

FRANCE, ASSIGNOR OF ONE-l-IALF TO MUN, Ol" MULHOUSE, ALSACE, GERMANY,

A Filth/l.

ivo. 831,234.

vtoothed wheels which roll f -orrectlyupon one sind the saune straight ,rack or e plu-ne wheel gear accurately with one another. ll' now the rs1-ck or plone wheel he replaced bye shaping-tool of the form of one of the teeth thereof, in i ront oi' which the wheel-blank to hecut rolls, the said tool shapes or cuts out tooth-flanksol"Y e shape ctn-respoiuling to the diameter ofthe Wheel-hhmk. Now it will he obvious that in. cuttingr bevel-Wheels in this manner only one flank een he cut :it n time,

:is the spaces between the: teeth on the inside oi" the toothed periphery are narrower then :it the outside, and the ihin'ks of the teeth converge to the geomet riool apex ofthe cone. 'the successive cuttingl ol' the tivo flanks of the teeth is, however, tedious, und it is, turthermore, nevessery to :uljinit-eml regulate the ltool ftfter l(he cutting of eeoh'flnnk. These disadvantages een he ohviirted by employing two cutting-tools, its iu the crise oi cer'rnin bevel-wheel cuttin1-nniclrines'oi the temp let or pattern type, the seid uiting-tools simultaneously shapingr tivo tooth-llenks on the blank to be out. ting, however, the arrangement must be such that the shaping or euri in e; tools inc i' `e between them :t straight-sided 'tooth-s rice, so that there is provided practically e straightlinnked cutting-tooth space, the two tools beine' perinmiently edfusted end clenipedwith n constrained relaiiveniotion between thorn andthe wheel transversely lto .the exis there- Vof for the purpose of forming 'the rolling'v toothed surfaces, so es to sinnritfineousiy shape both flanks of e tooth with the necessf'try convergence in the case 'of bevel-teeth. ly this arrangement not only are the dised vontzrres attaching to the ahove-deserihg and what for this purpose ennnot be underestimated, not

. Specification of Letters Patent. Application filed October 12,1904. Serinl'Nd. 228,178.

French Republic, resid-- ',Qeau'ing, espeinirn'oved machine- Patented sept. 18,1906.

only can the wheel be cut tooth by tooth with onlyou sin ele adjustment ofthe cutting-tools', but by the simultaneous cutting 'of both flanks of a tooth the lateral pressures on the tools mutually com ensote one another, (at any rete at the mid le oi the cutting period,) whereby the danger of a distortion of the Wheel is diminished or completely obviated.

My invention provides, in connection with su eh cutting; mechanism, means for obtaining?,l si resultant rolling' motion of the blank, such means including n, blank-carrier having a. ,bearing device for holding the blnk,rneens for producing e transverse relative movement between the blank-carrier and cutters, means for rotating the blank, and Ineens guiding;r the letter. Such guiding ineens pref einbly comprises tWo' levers cooperating With the blank in such manner that theresultant motion imported to the letter correctly rolls Tit past the outtersr.;`

The accompanying: drawings illustrate a suitable arrangement for carrying outthe ini'vheels, Y.

ln the seid drawings, Figure 1 is a view illustratingr the mode of operation of the Inechine, which in general is based 'upon the principle oi the known. rolling method; but in lieu ol showingy the ivheel in positions which it essurnesin the course of one revolutionrelotively with .the pair of eut tin er-tools, which would correspond to the en' rnngement illustrate for the sake oi' eieorness the positions correspendi og to the various de ths of ont, which is the equivalent thereof as 'or ss the considerer' l tion oi the result to be otteined'is eoneerned.

Figs. 3 and, 3 two vertical seetions of the inechine through twoplones et right angles to one nnrgther. Figi. e is e plan view thereof,y partly in horizontal section; and Fig. 53's e detail view oi e devine for l hiank to be out in iront/oi' shaping toois or Gutters. f A

l sind 2 indicate lthe two sheping tools or cutters mounted in carriages, the seid tools or cnt-ters. being; errenged vertically irl-pereliel planes, so es to provide between them e streight-sided tooth-space, Fig. The een, liege-giiides 3 and fi ere adjustable in the vertier/l end horizentei pierres mound the eeml mon center iine oi ythe syste/in, toward the two adjusted vention es applied to the eutting'of bevel' d, there 'ere here shown roihng the wheelthe dider'ent i 'Y segmental feet 22L and 23 in such a manner which t-h'eaxisof the gear to be cut' is directed, so that 'they can be adjusted to the' requisite inclination and to the correct angle of a crank-'pin 9, with block 10,` and oscillates the 4com'fergence with respect te one another and clamped in position, as hereinafter explained.

Outside the standardr 5 is mounted the stepped ulley 6 upon the'shaft 7, Flgs. 2 and 3. he latter carries a disk 8, which has 19, Fig. 2, facilitates this adjustment to the necessary angle, and bolts 21 serve to y clamp the guides 3 and 4 after the adjustlinks 13 and 14 are ment has been eii'ected, Figs. 2 and 4. 'The bearings 22 and 23 of the pivots 17 and is canbe turned about the central'line O in circular guides on the lstandard 5 by means of that the two cutting edges of the tools can be adjusted so as to converge in accordance with the thickness of the tooth. Scales 24 and 25, provided at suitable points on the standard '5, facilitate this adjustment tothe requisite angle and-convergencefand bolts 26 and 27 serve for clamping the bearings 22 and 23 after the'adjustmenthas been'cflected, Fig.

4. `Since theA carriages 1 5 and 16 do n ot move parallel to the lever 12, as will be best seenjrom Fig. 4, the joints 28 and ,29 of the in the formof universal joints, Fig. 3.

The tools 1 and 2 and their driving mechanism are so arrangedthat the said tools can operate upon the tooth from the inside tol Ward the outsidethahis to say, from the smaller tothe larger diameter-whereby a smooth engagement'and motionare obtained', as inA this manner the cross-section of the shavingv gradually increases. Furthermore,

this arrangement enables the wheel-blank 30 to be supported externally at the bottom by a support 31vwhen thicker shavings are being i cut,-Fig. 2. The shaping-tools are held. in holders 32 and 33, which are pivoted upon pins 34 and-35. On the return motion of the 'tool-,carriages these tool-holders can yield,

While on the forward` or working stroke they are brought into the operative position by springs 36 and are held in this position against rigid supports. By this 'construe tion ofv tool-holder the removal of the tools is avoided as much as possible. The cutters themselves are of siinpleandstrong shape.

. The blank 30 to be cutis centered upon the pivot 37, Fig. 2, which is inserted in the bush 39, the blank being thenI pressed tightlyagainst vthe latter by the screw 38.

4U indicates adjusting-washers introduced between the blank and the bush. The 'said bush is connected tothe wheel 41 of the division device, the division-worm .42 of which. 'is here arranged to be operated by hand, al'- though it can be'providedwith an automatic drive'and is carried b thecasing 43, inclosing the division-Whee 41, The upper part 44 of the casing 4 3 carries an arm 45, extending downward and formed with a longitudipin 47, ada ted to be locked in any position in the said s ot, Figs. 2 and 4. The casing 43 also carries a boss 48, which can turn in the socket 49 and is secured in position by means of a nut 50. :The socket 49 is carried by a sector-shaped bearing-bracket 51, which can turn upon a pivot 52 and can be adjusted, by a worin 53 engaging the toothed periphery of the blank-carrier 56, with the assistance of a scale 54, to the angle of 'the wheel to be cut, thc axis of which must obviously pass through the middle -point O. Screws 55 are employed for clamping the bearing 51 in position after the adjustment is effected. Th". blankfcarrier 56, which carries the bearing 5i bythe pin 52, is itself rotatably mounted upon-the column 5 and can be turned bythe Worm-wheel 57 and worm 58. This worm 58 is during the o eration of the machine actua ted by suitab e ratchet mechanism 64, 65, and 66, Figs. 2, 3, and 4, the'levei 64 of whichl is reciprocated from the driving-pulley t6,- which for this purpose is provided with a heart-shaped groove 59. through the medium of the lever 60, shaft 61, lever 62, and rod 63, this reciprocating motion :being communi cated by the pawl .65 to the ratchet-wheel 66, mounted upon the spindle 67 of the worm 58. This ratchet mechanism has for lits object to intermittently move the carrier 56 with the wheel-blank 30 relatively with the tools 1` and 2 and in a direction transverse to the axis thereof, so that the blank is moved step b step 'from a position on one side of the too s to a position' on the other side inorder during this movement to be subjected to the cutting action of the tools 1 and. 2. After each complete stroke or to-andelfro movement ofthe tools the blank-carrier 56, and thereby the wheel-blank, is moved Yforward one step. Forthe requisite shaping 0'1"' the teeth of the wheel it is, however, necessary that the blank shall simultaneously with this intermittent. move` ment also intermittently turnwthat is to say, shall gradually rolL---withrespect to the IOC tools. Thisis necessary for giving the teeth the proper profile. For this purpose the following device is provided. l

As is well known, a point on circle which rolls along a flat path describes a cycloid, the centers of curvature .of which form its evolute. ln order now to obtain a correct rolling of the Wheel-blank without complicating the cohstruc-tion of the machine, circularly-curved v nal groove 46, in which is adjustably :Fitted a slotted fork-levers 68 and 69', Figs. 4 and 5, are provi :led with their su porting-pivots 7 0 and 71 adjustably secure symmetrically Yto the center 7 4 of curved slotted rail 72, iitted tov the standard and representingthe evolute of a cycloid. The slotted levers 68 69 are mounted on sockets, Fig. 4, supported on the pivots 70 71, respectively, and to which they are detach-ably coupledfor example,

by means 'of a set-screw-so that the said levers can swivel throughl the sockets on the supporting-pivots 70 71. The forked ends of the levers 68 69 embrace the in 47, secured to the arm at the height oi) the pitchcircle of the wheel, and are loaded with a weight 73, which tends to depress said levers 69 and 70. It now the blank-caiier moves circu'larly, so that the upper end of the axis 38 of the wheel-blank 30 moves in a horizontalyplane from left to right in the direction. .of the arrow in Fig. 5, the lever-arm 45, on which is adjusted the pin 47, tends to oscillate to the left under the action of the weight 73, which draws the pin 47 downward, such pinbeing guided by the lever 68, swivehng onits pivot 70, which is firmly secured tothe supporting-rail 72. The pin 47'l'ies 'in the inner portion of the tork oi the lever, so that it is constrainedl to describe a circular arclike curve representing substantially adescending portion of a cycloid which is the geometrical path ofthe pin 47, indicated by the left-hand curved ,line in Fig. 5. Of course the lever 69, which also engages the pin 47, is moved downwardly by the latter'. In this way the intermittent transverse circular ,movement oi the blank-carrier 56',l in conjunction with the downward movement of f theweight acting against the lever-arm 45,

which tends torotjate the wheel-blank, results in an intermittent rolling motion pf the casing 43 and the-wheel-bla'nk carried thereby. On' arriving at the point 74 the guidepin 47 is held between the two guide-levers 63 69, and as the circular movement of the blank-carrier 56 continues Astep by step in the same direction the said guide-pin 47 is then forced to rest against the guide-lever 69, by which it is guided soy as to describey substantially the rising symmetrical portion of the cycloid, the guide-lever 68 being released. It

is to be noted that the adjustment of the pivcircle becomes ots 7G and 7l on the supporting-rail 72 deends upon the position oi the pin 47 relatively with the wheel-axis (see Figs. 2 and ithat is tesay, on the diameter of the wheel to be cut--since the geometrical rolling" greater or smaller, and consequently the curvature of the path ofthe, guide-pin 47 varies in accordance therewith. The operation of the machineis, shortly, as follows: After the blank 30 to b'c'utis sei cured in position and adjusted to the proper angle by the worm 53, with the assistance of thescale 5 4, the. guide-pin 47 is secured in the pitch-circle of the wheel-blank, Fig. 2-'-that is to sa'y, at the point 74, Fig. 5-when the arm 45 isvertical. The supporting-pivots 70 and 71`of the guide forked levers .68 and 69 are then securedin the .proper position and the wheel 30, by turning the blank-carrier 56 by meansof the hand-operated worm 58, is

rolled until it lieswithin reach of the operating-tools. The tools 1 and 2 are then secured in the proper level position in their holders and the guides 3 and 4 of the tool-carriagesare adjusted and secured in positions according to the depth and thickness of the teeth to be cut. It now the machine be started, the blank-carrier 56 isintermittently turned, through the medium of the ratchet mechanism 64 65 66and the-worm-gear 57 58, so that the wheel-blank 30 is gradually rolled more and more over the reciprocating tools, which latter simultaneously cutout inv the `blank two spaces, leaving between them a shaped tooth, Fig.`1. When a tooth is cut in this manner, the blank, by the backward rotation of the blank-carrier 56, (which is eiiected by hand or otherwise,) is returned to its normal position, rotated through one division, by meansv of the worm 42 of the division device andagain operated for the cutting out of the next tooth, and so on. For larger wheels it is advantageous to arrange the support for the wheel to be cut in guides onv the bearing 51, so as to be able to slide and be. adjusted, together with the wheel, vwith respect to the common center, this'arrangement being used as a substitute for the adjustment by means of the washers 40.. In the case of cutting spur,

chiefiy bevel-wheels, onl the rolling principle,

having two simultaneously.-reciprocating cutters or tools arranged. to providebetween them a straight flanked tooth-space, means 'for guiding said cutters, means for imparting a vto-and-ro movement Ato said cutters, a.

'l movable blank-carrier having a bearing device forrotatably supporting the blank,

means, for producing an intermittent Atransverse relative movement between the blank- .carrier and thecu'tters, independent means -forrotatin'g the blank on its bearing device diiringfsuchrelative transversel movement, a lever-arm connected to the blank and provided with a guide-pin at the height of the p,

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the' parts 68 69 72 being pitch-circle of the wheel to'pbe cut, and two guide members arranged on opposite sides of the vertical plane of thecutters, said guideV members engaging said guide-pin, and each' pendently-adjustable means forguiding said cutters, means for imparting a to-and-fro mox ornent to saidcutters, a movableblankcarrier having a bearing device for rotatably supporting 'the blank, means' for producing anv intermittent transverse movement of the blank-carrier relatively to the path of the cutters, independent means for rotating the blank on its bearing device during'such transverse movement of the blank-carrier, a leverarm connected to the blank and vrovided with av guide-pin at the height of t e pitchcircle of the wheel to be mit, and two guidelevers arranged on opposite sides of the vertical plane'of the cutters, said Aguide-levers engaging said guide-pin, and each being adapted to guideit inan arc-like path so as go to obtain a resultant rolling m'ot1on of the blank, substantially as set forth.

3L A? machine for cutting toothed wheels, chiefly bevel-wheels, 'on the rolling principle, having two simultaneously -reciprocating cutters or tools arranged to Aprovide between them a 'straight flanked tooth-space, independently-adjutable means for guiding said cutters, means'for imparting a to-and-fro -movement to said-cutters, a movable blankcarrier-.having a bearing device for rotatably 4supporting theblank, means for producing an intermittent transverse movement 'of the'- blank-carrier relatively to the path of the cutters, independent means for rotating the 4 5 blanken its bearing device during such transverse movement of the blank-carrier, a leverarnficonnected to the blank and rovided with'a guidein at the height of t ie pitchcircle ofthe eel to be cut, two guide-levers .arranged'on opposite lsides of the vertical plane of the cutters, said levers engaging said guide-pin, and a supporting-rail .on which said guidelevers are adjustably pivoted, said levers each being adapted to guide said pin in` an arc-like path so asA to obtain-a rcsultant rolling motion of the blank, substantially asset fort-h, I. 7

*4. Amachne for cutting toothed Wheels,4

chiefly bevel-wheels, on. the 'rolling principle, having two simultaneously-reciprocating critters or tools arranoed to provide between them a' straight Vflanked tooth-space, findependently-adj'ustable means for guiding'said cutters, lmeans for imparting a to-and-fro movement to said cutters, a vmovable blankan intermittentvtransverse movement of the blank-carrier relatively to the path of the cutters, independent means for rotating the blank on its bearing device during such'transcarrier having a bearing device for rotatably supporting the blank, means for producing verse movement ofthe blank-carrier, a 1ever ,I

arm connected to the blank-and provided' .with an adjustable guide-pin, two guide-leversarranged on opposite sides'of thevertical' lane of the cutters; said levers engaging sai guidepin, and a supporting-rail on which said guide-levers are adjustably ivoted, each of said levers being designe to guide said pin in an are-like path so aste ob-' carrier havin(r a bearing device for rotatablysimultaneously reciprocating supporting tlieblank, means for producing i an intermittent transverse movement ofthe blank-carrier relatively to the path ofthe cutters, a lever-arm connected to the blank and provided with aguide in at't'he height of the itch-circle of the w eel to lbe cut, ay snspen ed weight onsu'ch guidein-and hav-h ing a tendency to rot .tte the blan on its bear-l A ing device, and two forkedguide-levers arranged on oppositesides of the vertical plane'l of the cutters, each of such levers engaving saidguidein and being adapted to guide it in an arc-li e path so as to obtain a resulting rolling lmotion of the blank, lsubstantially as' set forth.

In witness whereof I have hereunto signed my name, this 26th day of Se tember, 1904, in the presence of two subscribing Witnesses.

' GEORGES NARDIN.

Witnesses:

lonN BAKER, GEORGE E. LIGHT. 

